Supreme Court nominee Brett Kavanaugh is issuing a strong denial in response to reports that a woman accused him of sexual misconduct in high school.

Controversy ignited after Sen. Dianne Feinstein, D-Calif., said Thursday that she had received information from an individual regarding Kavanaugh and she had referred the matter to federal investigative authorities. She said the woman refused to come forward and requested confidentiality. Feinstein is the ranking Democrat on the Senate Judiciary Committee, which has scheduled a Sept. 20 vote on Kavanaugh’s confirmation.

The New Yorker reported on Friday that the unnamed woman wrote a letter to her congresswoman saying that she had attended a party when Kavanaugh was in high school, and that during the party, Kavanaugh had held her down, covered her mouth with his hand and tried to force himself on her. The New Yorker reports that the woman said that Kavanaugh and a classmate had turned up the music in the room to muffle her protests, and that the woman was able to break free.

The New York Times followed with a story reporting the same allegations. Its report is based on three people familiar with the letter.

Kavanaugh responded with this statement: “I categorically and unequivocally deny this allegation. I did not do this back in high school or at any time.”

Kavanaugh’s classmate told the New Yorker, “I have no recollection of that.”

The letter also reached Feinstein, who at first did not share it with other Democrats on the Senate Judiciary Committee. She briefed Democrats about the letter on Wednesday.

White House spokesperson Kerri Kupec called Feinstein’s announcement of the referral an “11th hour attempt” to delay Kavanaugh’s confirmation.

The Senate Judiciary Committee released a letter on Friday morning from 65 women who knew Kavanaugh when he attended high school between 1979 and 1983. “For the entire time we have known Brett Kavanaugh, he has behaved honorably and treated women with respect,” the letter said.

According to a July article in Business Insider, Kavanaugh is a graduate of Georgetown Preparatory School, an all-male Jesuit boarding school in Bethesda, Maryland, that Justice Neil Gorsuch also attended. Kavanaugh graduated in 1983, and Gorsuch in 1985, according to the school’s notable alumni page.